Field
The present invention relates generally to the cultivation and processing of small aquatic photosynthetic organisms such as algae, aquatic species, and the like, including the small aquatic plant floating aquatic species such as duckweeds.
Description of Related Art
Lemnaceae is a family of flowering plants, also known as the duckweed family, as it contains the duckweeds or water lentils. Duckweeds include the genera Spirodela, Landoltia, Lemna, Wolffia, and Wolfiella. Duckweeds are fast-growing, high-protein-yielding, and high-pigment-containing monocotyledonous plants and are classified as macrophytes. There are greater than forty species of duckweed worldwide, but they are most abundantly found in moderate climates of tropical temperate zones. When confronted with temperatures below about twenty degrees Celsius, duckweed plants form a non-buoyant structure called a turion, which sinks to the bottom of the pond and remains dormant until warmer conditions return.
Duckweed is an important food source for waterfowl and is eaten by humans in some parts of Southeast Asia. Duckweed additionally provides shelter for a number of water species, such as frogs and fish, while simultaneously aiding in bioremediation of its native environment by absorbing excess mineral nutrients, particularly nitrogen and phosphates. Duckweed grown on sewage or animal wastes normally does not contain toxic pollutants and can be fed to fish or to livestock, or spread on farmland as fertilizer. However, duckweed that is to be used for human or animal consumption involves a retention period in clean water to ensure that the biomass is free of water-borne pathogens. Duckweed and lemna are used interchangeably in the application.